1. Field
The present disclosure herein relates to a semiconductor memory device and a method of manufacturing the same, and more particularly, to a three-dimensional semiconductor memory device having improved electrical characteristics and a method of manufacturing the same.
2. Description of the Related Art
In order to satisfy user's demand for excellent performance and low price, it is required to increase degree of integration of a semiconductor device. In the case of a semiconductor memory device, since the integration degree is an important factor which determines a product price, higher integration degree is particularly required. In the case of a typical two-dimensional or planar semiconductor memory device, the integration degree is mostly determined by an area occupied by a unit memory cell. Therefore, the typical memory device is greatly affected by a level of a technology for forming a micro pattern. However, since high-priced equipment is needed for forming the micro pattern, increasing the integration degree of the two-dimensional semiconductor memory device is limited.
For overcoming this limitation, a three-dimensional semiconductor memory device provided with three dimensionally arranged memory cells has been proposed. However, for mass production of the three-dimensional semiconductor memory device, it is required to develop fabricating technology so that manufacturing cost per bit may be lower than that of the two-dimensional semiconductor memory device and reliable production properties may also be obtained.